Planooraph co



C. S. RHOADS, Jn.

ANSWER BACK FOR SIGNALING SYSTEMS. APPLICATION FILED FEB. 25. I953.

1 ,309, 3 69 Patented July 8, 1919.

CHARLES STANLEY RHOADS, JR., OF INDIANAPOLIS, INDIANA.

ANSWER-BACK FOR SIGNALING SYSTEMS.

Specification of Letters Patent.

Patented July 8, 1919.

Application filed February 25, 1918. Serial No. 218,943.

To all whom it may concern Be it known that I, CHARLES STANLEY RHoAns, J12, a citizen of the United States, residing at Indianapolis, in the county of Marion and State of Indiana, have invented a certain new and useful Improvement in Answer-Backs for Signaling Systems, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to answer back apparatus for signaling systems and has for its object the provision of an improved answer back system which is of particular use in connection with telegraph or similar systems.

In the specification and drawing I have shown a system of this nature as applied more particularly to a telegraph system, as the application of the invention to other systems will be readily apparent from this description.

I will describe this form of my invention by referring more particularly to the accompanying drawing illustrating this particular embodiment.

In this drawing I show a Morse telegraph line 1 which as customary extends directly through a plurality of stations. For the sake of clearness I have merely shown a sending station A and a receiving station B. In practice, of course, there will be a great number of such receiving stations, but as stated, there is no need of illustrating more than one for the purposes herein.

At the'sending station I have shown a telegraph line 1 having the key 2 with customary short circuiting switch 3, the telegraph line 1 being at this sending station connected to earth at 4 through the interposition of the telegraph battery 5. A relay 6 is also shown at this sending station oper ating the customary sounder which is associated in the local circuit with the battery 8. The substations are each provided with a selector 9 which may be of the customary Grill telegraph selector type as shown for instance in his Patent No. 906,523 and having the operating winding 10 together with the contacts 11 and 12 which are brought into circuit closure when a definite dot and dash code signal has been passed through the circuit including the coil 10. The construction of this selector is well known in the telephone art and it is thought a further description of this code selector will not be needed for the purposes herein. The opposite extremity of the line 1 again is grounded at 13 through a battery 11. This selector 9 at the station E is adapted to operate the call bell 15 whenever the proper code is received over the line 1 by the selector 9.

The circuit shown for station B is amplified so that it is fully equipped for use in connection with concentration units used upon tables at those telephone exchanges where many lines enter. The line 1 is thus shown at the substation B and is provided with two jacks 16 and 17 respectively, to either of which jacks connection may be made by the plug 18 being directly connected to a relay l9 and telegraph key 20. The jacks 16 and 17 are at opposite sides of the table so that connection may be made from either side. In connection with tho jacks 16 and 17 respectively I provide lamps 21 and 22, which are illuminated whenever a call has been received over that particular line, which call remains unanswered. There is further provided a pilot relay 23 to control a pilot lamp 2-1, which pilot lamp and relay may be common to a plurality of entering lines to signal an operator so that he may answer the call that has come in. The jacks are provided with sleeve contact springs 25 and 26 respectively and with tip contact springs 27 and 28 respectively. The springs 27 and 28 are insulated from, but cause the simultaneous movement therewith of cooperating contact springs 29 and 30. Back contacts 31 and 32 are respectively provided for the springs 27 and 28 and back contacts 33 and 34: respectively are provided for the springs 29 and 30. Call bell 15 is controlled intermediate the selector 9 by a double wound relay 35 having the coils 36 and 37 respectively, which are wound to one hundred ohms resistance and thirty thousand ohms resistance. The relay 35 has an armature 38 which is connected to ground at 39, this armature having the front contact 40. The call bell has an operatin mag net '11 controlling an armature raving a back contact 43. The armature 42 also causes the simultaneous movement therewith of a contact spring 44, which however is insulated from the arnn-iture 42. and this contact spring 44 cooperates with a back contact 45. The pilot relay 23 has an armature 16 which is directly connected to ground at i? through the interposition of the preferably fifty-two volt battery 48. One terminal oi' the pilot lamp 21 is connected to ground at 19. A locking relay is provided having the armature 51 cooperating with the front contact 52, one terminal of of the coil 50 being directly connected to ground at The locking relay 50 preferably has about four ohms resistance and the pilot relay preferably is wound to the same resistance.

In connection with the selector 1 provide resistances 51 and which are of five hundrcd and one hundred ohms resistance respectively. The entering Morse line 1 is connected to the jacks 113 and 17. This circuit may be traced by following the entrance of the left hand section of the Morse line 1 which is directly connected to the springs 25 and 26.

The springs 25 and 26 are connected by means of a conductor 56 with the left hand terminal of the coil 36 of the relay 35, the right hand terminal of which is connected by means of conductor 57 with the back cont-act A conductor 58 then connects the coiiperating contact spring 1-1 to the right hand terminal of the coil 37, from which a conductor 5 extends which is con nectcd directly to the back contact 32. A conductor connects the contact spring 28 with the back contact 31 and the coiipcrating tip spring 27 is then connected to the right hand section of the Morse line 1. The Morse circuit thus extends through the substation 5 normally with nothing included in its circuit except the coil 36 of the relay 35. Should the plug 18 be inserted in either jack 16 or 17, then the circuit including the relay 35 is broken at either the back contact 31 or back contact 32, but the telegraph instruments associated with the plug are thereupon serially included in the Morse line.

Assume now that the plug 18 is not in either jack and that a code signal is being received over the line 1, this code signal actuatcs the relay 35 so that its armature 38 moves in unison, thereby transmitting the code to the selector 9 over the circuit which extends from the ground 39, armature 38, front contact 40, conductor (31. coil 10 of the selector 9, resistance 54., conductor 62, conductor 63, battery 48 to ground at 17. The selector 9 is thus actuated in response to the code which is being transmitted over the line circuit 1. If the proper code is received to cause a response on the part of the selector 9, then the contacts 11 and 12 are closed. as is well understood. A closure of these contacts establishes a circuit for the call bell 15. It also be said that immediately the contacts 11 and 12 are closed the circuit of the elements 38 and -10 remains closed so long as the operator at station A wishes to continue the operation of the call bell 15. Thus, after the operator at the station A has rung the bell 15 a suliicient length of time, an opening of the circuit of the line 1 will cause a release of the elements 38 and 10, whereupon the selector 9 is restored to normal position. The circuit which is used to operate the call bell when the proper code has been received may be traced from the ground at 47, battery as, conductor 63, resistance 55, contacts 12 and 11, conductor 64, electromagnet 41, conductor 65, contact 43, armature 12, conductor 66, through the relay 50 to ground at 53. The bell thus operates intermittently by reason of the intermittent character of the contact between the elements 42 and 43. The bell continues operating so long as the circuit between the elements 38 and 10 remains closed. This circuit also causes the locking relay 50 to draw up its armature 51 and thereby establish contact between the elements 51 and 52,

whereupon a circuit is established extending from the ground 53, through the coil 50, armature 51, front contact 52, conductor 6?, spring 29, back contact 33, conductor (38, lamp 21, conductor 69, back contact 3%, spring 30, lamp 22, conductor 70, pilot relay 23, battery e8, to ground at 4:7. This circuit then remains in its locked condition so long as the circuit to either of the back contacts 33 or 34 is not broken by the insertion of the plug 18 into either jack. The insertion of the plug into either jack however restores this circuit and extinguishes lamps 21, 22 and 24. It must be understood that these lamps 21, 22, and 24 continue burning even after the operator at station A has discontinued the operation of the call bell 15 so that a permanent signal is established to call an operator to that particular line as soon as the operator is available.

N ow in order to prevent breaking of the circuit between elements 38 and 40 by the opening and closing of the circuit between the elements 42 and 43, I provide the auxiliary winding 37 for the relay 35. This winding 37 is normally short circuited by the establishment of contact between the ele ments 4% and 45. \V hen the call bell is opcrating, however, to open the circuit through the coil 36 by reason of the breaking of the contact between elements 4 1 and 45, then current still passes through the coil 37, which current is enough to maintain the armature 38 attract/ed although the current would not be enough to attract the armature were it in its unattracted position. The coil 37 is thus merely a holding coil to prevent the release of the armature 38 by reason of the making and breaking of the contacts at the call bell. However, it will be readil apparent that the actuation of the call bell 'IOO thus serves to change the resistance included in the line 1 at the substation B from one hundred ohms to thirty thousand ohms by reason of the alternate inclusion of the coil 36 and then the coil 37 inthe circuit when this call bell is 0 crating. This check in the resistance is su cient to cause an actuation of the relay 6 at the sending station A to indicate to the operator at that station that the call bell 15 of the substation B is responding to the call.

From what has been thus described it will be readily apparent that the actuating call bell has vibratory means which actually cause a change in the circuit conditions of the line 1 sufiicient to operate the relay at the sending station, whereby the sending station receives an answer back signal.

Those skilled in the art will readily understand that my invention may be applied to different systems and under different conditions without departing from its spirit.

Having however thus described one form which my invention may take, what I claim as new and desire to secure by Letters Patcnt is:

1. A signaling system of the character described comprising a signal sending station and signal receiving station, an electromagnetic signal receiving device at the signal sending station, a line circuit extending between said signal sending and signal receiving stations, a code selector at the signal receiving station, a signal controlled thereby having a vibrating armature and cooperating contact, said code selector having means operable upon the response of said code selector to cause a continuous actuation of said signal during the maintenance of a closed circuit through said code selector, and means including an auxiliary contact under the control of the vibrating armature of said signal to effect changes in the circuit condition of the said line circuit to thereby transmit a signal to operate the signal receiving device at the signal sending station.

2. A signaling system of the character described comprising a signal sending station and signal receiving station, an electromagnetic signal receiving device at the signal sending station, a line circuit extending be tween said signal sending and signal receiv ing stations, a code selector at the signal receiving station, a signal controlled thereby having a vibrating armature and cooperating contact, said code selector having means operable upon the response of said code selector to cause a continuous actuation of said signal during the maintenance of a closed circuit through said code selector, and means including an auxiliary contact under the control of the vibrating armature of said signal to effect changes in the circuit condition of said line circuit to thereby transmit a signal to operate the signal receiving device at the signal sending station, during maintenance of the closed circuit condition of said code selector.

3. A signaling system of the character described comprismg a signal sending station and signal receiving station, an electromagnetic signal receiving device at the signal sending station, a line circuit extending between said signal sending and signal receiving stations, a code selector at the signal re ceiving station, a signal controlled thereby having a vibrating armature, said code solector having means operable upon the response of sald code selector to cause a continuous actuation of said signal during the maintenance of a closed circuit through said code selector, and means under the control of the vibrating armature of said signal to effect changes in the circuit condition of said line circuit to thereby transmit a signal to operate the signal receiving device at the signal sending station, said means including a pair of electromagnets of widely different resistances.

4. A signaling system of the character described comprising a signal sending station and signal receiving station, an electromagnetic signal receiving device at the signal sending station, a line circuit extending between said signal sending and signal receiving stations, a code selector at the signal receiving station, a signal controlled thereby having a vibrating armature, said code selector having means operable upon the response of said code selector to cause a continuous actuation of said signal during the maintenance of a closed circuit through said code selector, and means under the control of the vibrating armature of said signal to effect changes in the circuit condition of said line circuit to thereby transmit a signal to operate the signal receiving device at the signal sending station, during maintenance of the closed circuit condition of said code selector, said means including a pair of electromagnets of widely different resistances.

5. A signaling system of the character described comprising a signal sending sta tion and si al receiving station, an electromagnetic signal receiving device at the signal sending station, a line circuit extending between said signal sending and signal receiving stations, a code selector at the signal receiving station, a signal controlled thereby having a vibrating armature, said code selector having means operable upon the response of said code selector to cause a continuous actuation of said signal during the maintenance of a closed circuit through said code selector, and means under the control of the vibrating armature of said si nal to effect changes in the circuit condit on of said line circuit to thereby transmit a signal to operate the signal receiving device at the signal sending station, said means including a pair of electromagnets of widely different resistances, and an auxiliary vibratory contact making and breaking device operable conformably to the operations of said signal.

6. A signaling system of the character described comprising a signal sending station and signal receiving station, an electromagnetic signal receiving device at the signal sending station, a line circuit extending between said sending and signal receiving stations, a code selector at the signal receiving station, a signal controlled thereby having a vibrating armature, said code selector havin means operable upon the response of said code selector to cause a continuous actuation of said signal during the nuiintonance of a closed circuit through said rode selector, and said means under the con trol of the vibrating armature of said sig nal to efiect changes in the circuit condition of said line circuit to thereby transmit a signal to operate the signal receiving de vice at the signal sending station. and maintain the closed circuit condition of said code selector, said means including a pair oi electromagnets of Widely different resistances, and an auxiliary vibratory contact making and breaking device operable coir formably to the operations of said signal.

7. A signaling system of the character described comprising a signal sending station and signal receiving station, an eleetromagnetic signal receiving device at the signal sending station, a line circuit extending between said signal sending and signal receiving stations, a code selector at the signal receiving station, a signal controlled 1-,maao

thereby havi a vibrating armature, said code selector aving means operable upon the response of said code selector to cause a continuous actuation of said signal during the maintenance of a closed circuit through said code selector, pilot lamps and a locking relay controlled by said code selector, and means under the control of the vibrating armature of said signal to effect changes in the circuit condition of said line circuit to thereby transmit a signal to operate the signal receiving device at the signal sending station.

8. A signaling system of the character described comprising a signal sending station and signal receiving station, an electromagnetic signal receiving device at the signal sending station, a line circuit extending between said signal sending the signal. receiving stations, a code selector at the signal receiving station, a signal controlled thereby having a vibrating armature, said code lector having means operable upon the re sponse of said signal during the maintenance of a closed circuit through said code selector, pilot lamps and a locking relay controlled by said code selector, and means under the control of the vibrating armature of said signal to effect changes in the circuit condition of said line circuit to thereby transmit a signal to operate the signal re ceiving device at the signal sen-ding station, and maintain the closed circuit condition of said code selection In witness whereof I hereunto subscribe my name this 4th day of February, A. D. 1918.

CHARLES STANLEY RHOA-DS, JR.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. O. 

